Obesity is an important pediatric health problem associated with risk of complications in childhood and increased morbidity and mortality throughout adult life. The prevalence of childhood obesity has increased, and the prevention and treatment of obesity have emerged as an important focus of pediatric research and clinical care. The aim of this study is to assess the prevalence of obesity among preparatory school pupils in Assiut District which lies in the mid of upper Egypt and its possible risk factors. A cross sectional study was conducted among preparatory school pupils (1048) in Assiut District. A questionnaire was fulfilled by the participants. Calculation of weight categories was done using body mass index (BMI). The prevalence of overweight and obesity was 19.9% and 19.1% respectively. Low level of maternal education, rural residence, and low socioeconomic status were significantly associted with obesity. In conclusion, the prevalence of overweight and obesity among preparatory school children in Assiut District is high synchronizing with the global rate. Obesity became a serious and increasing health problem in Egypt like the rest of the world. Strategies to manage and prevent further spread of this pandemic should be undertaken.